With the development of information and communication technology, there is a tendency to integrate information and communication technology into various fields such as the medical industry, healthcare, remote meter reading, smart home, and smart car. In particular, there is a tendency to use IoT (internet of things) technology to share information by connecting objects used in various fields through a network.
For example, in the medical industry, it is possible to share health information necessary for patient health maintenance with a principal physician in real-time by using IoT-based devices and to prescribe medicine and cope with the same in real time.
However, in recent years, security incidents where unauthorized users browse collected information frequently occur when information collected from each source object is transmitted to a destination object. Accordingly, there is a trend of applying security authentication to IoT so as to address security incidents.
For example, when a source object that collects data, such as a patient's bio-signal information and disease history information, transmits corresponding data to a destination object in the medical industry, an authorized user reads data from the destination object after security authentication.
As an example of a security authentication method, there is a method wherein hardware that stores key information (e.g., a private key, a public key, and the like) necessary for authentication based on a nonvolatile memory and performs security authentication using the stored key information.
However, a conventional authentication method of using hardware has a problem that hackers can leak key information, which is stored in a nonvolatile memory, through various memory reading methods.
In recent years, to address such problems of an authentication method using hardware, a technology of making copying physically impossible using a nanomaterial-based physical unclonable function (PUF) circuit is rapidly emerging.
A nanonet material may include at least one of a nanowire and a carbon nanotube (CNT).
A nanowire is a wire structure having a nanometer-scale size, and a carbon nanotube is a structure having a tubular shape wherein hexagons, each of which is composed of six carbon atoms, are connected to each other.
A nanonet material, such as a nanowire, a carbon nanotube, or the like, is a metallic or semiconductive material, and is used in various devices such as semiconductors, flat panel displays, batteries, ultra-high strength fibers, biosensors, and Braun tubes.
However, a nanonet material has a disadvantage in that it is difficult to control chirality thereof in a growth process and thus it is difficult to realize a large-area integrated circuit. To address such a disadvantage, research into eliminating or alleviating defects occurring during growth of a nanonet material is actively underway.
However, research into utilizing defects during growth of a nanonet material has not yet been performed.
A carbon nanotube (CNT), as a nanomaterial, is a new material having a tubular shape wherein hexagons, each of which is composed of six carbon atoms, are connected to each other, and is used in various devices such as semiconductors, flat panel displays, batteries, ultra-high strength fibers, biosensors, and Braun tubes.
However, since such a carbon nanotube has a growth temperature of 900° C. or more, there are difficulties in growing the same on a plastic substrate.